Electric railway-signal



(No Model.)

W. STEVENS 81; H. J. HOVEY. ELECTRIC RAILWAY SIGNAL Patented June30,1891.

WITNESSES:

UNITED STATES.

PATENT Clarion.

\VINSLOW STEVENS AND HENRY J HOVEY, OF NEW HAVEN, CONNECTICUT,

ASSIGNORS TO THE HALL SIGNAL COMPANY, OF PORTLAND, MAINE.

ELECTRIC RAILWAY-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 455,266, dated June30,1891.

Application filed November 11, 1890- Serial No. 371,026. (No model.)

To all whom it may concern;

Be it known that We, WINsLow STEVENS and HENRY J. HOVEY, citizens of theUnited States, residing in New Haven, county of New 5 Haven, and Stateof Connecticut, have invented certain new and useful Improvements inElectric Railway-Signals, of which the following is a specification.

Our invention relates to electric railwayto signals, with particularreference to automatic apparatus in which moving trains act uponcircuit-controlling devices to alter the position of the signals toblock and clear successive sections of the track.

The invention is designed to prevent disaster or irregular operation dueto the failure of the apparatus to properly perform its functions.

The invention consists of the following-described apparatus.

In the accompanying drawing, the figure represents a diagram of thecircuits controlling one section or block of a track.

The signal is represented by S. It is usually located at the beginningof a section.

3 represents a track-instrument consisting of a circuit-breaker operatedby the Wheels of a train on its entrance to the section. This instrumentcontrols the circuit of battery B, including the signal and a relay R,the armature of which is adapted to make and break this circuit at thepoints 4. This circuit is normally closed, and while complete holds thesignal disk or blade in the position of safety, but as soon as it isopened the signal drops by gravity to danger. The circuit is, therefore,the blocking-circuit.

represents a normally-open circuit-closing track-instrument located ator beyond the end of the section or block and included in second circuitfrom battery B, which circuit also includes relay R and magnet M. Thefunction of this circuit is to reset the signal to safety as a'train ispassing out of the section or block, and is commonly known as theclearing-circuit. The armature of magnet M controls a complete shortcircuit m of the battery B, including the relay R.

1) indicates a cell of battery inserted in the clearing-circuit inseries with the main battery B. Its function will be set forth in thedescription of the operation, which will now be given. When S is atsafety, a train enters the block and momentarily breaks the circuit ats. This devitalizes the signal-magnet and allows the signal to fall bygravity to danger. It also devitalizes relay R, which permanently opensthe blocking-circuit at q". The signal remains at danger then until thetrain reaches the end .of the section, and temporarily closes theclearing-circuit at 0 through R, whereat, 8 being in its normal closedposition, the blocking-circuit is completed at r and the signalSliftedto safety.

So far described this is the common mode of operation of this class ofsignals; butit some-. times happens that even after a train has passedout of a section the signal remains at danger for an indefinite timeandprevents the farther movement of trains. Investigation has shown thatthere are two causes for this-first, that the clearing-instrument 0 maystick and hold both the clearing and blocking circuits closed, in whichcase the battery B, being split, may or may not be strong enough to liftthe signal, and, second, the wires of the clearing circuit may becomeaccidentally crossed and produce the same result. Therefore the magnetM, controlling the short circuit :r, and the battery I) are placed inthe clearing-circuit. Their operation is as follows: When theclearing-circuit is closed,.magnet M and relay R become energized, thusclosing both the blocking-circuit and the short circuit or. The shortcircuit, however, is so complete that the blocking-circuit gets noappreciable current at all, the result being that the signal is heldpositively at danger until the clearing-circuit opens, which it normallydoes when the last wheel of a train 0 passes out of a section. If,however, the apparatus becomes deranged, so as to cause the instrument 0to stick, or a cross of the Wires of the clearing-circuit takes place,then a: is held closed positively, and, the danger-sig- 5 nal remainingin sight, an abnormal space of time is indication that the apparatus isout of order, Battery 6 insures that the short circuit a: will be heldclosed. If this battery were not utilized, the portion of the currentIOQ of battery B flowing in the clearing-circuit. might not besufficient to hold the circuit to closed. The armature of magnet Mwould, therefore, vibrate, and might result in setting the signal tosafety.

Having now described our invention, We claim- 1. In an electric railwaysystem,the combination, with a blocking andaclearing circuit, bothemanating from the same battery, of a short circuit for said battery,and a magnet in the clearing-circuit controlling said short circuit, anda second battery in the clearing-circuit, for the purpose set forth.

2. In an electric railway signaling system, the combination, with ablooking and a clear-

